Jan Kiszka wrote:
> Philippe Gerum wrote:
>> We should indeed postpone this just in case the upper layer indexes the extra
>> state on the minor value. We can also simplify a few things doing so.
>>
>> --- ksrc/nucleus/pipe.c      (revision 4565)
>> +++ ksrc/nucleus/pipe.c      (working copy)
>> @@ -77,11 +77,9 @@
>>
>>  static inline void xnpipe_minor_free(int minor)
>>  {
>> -    if (minor < 0 || minor >= XNPIPE_NDEVS)
>> -            return;
>> -
>> -    __clrbits(xnpipe_bitmap[minor / BITS_PER_LONG],
>> -              1UL << (minor % BITS_PER_LONG));
>> +    /* May be called with nklock free. */
>> +    clrbits(xnpipe_bitmap[minor / BITS_PER_LONG],
>> +            1UL << (minor % BITS_PER_LONG));
> 
> Bad news: This doesn't fly as is. All modifying operations on
> xnpipe_bitmap must be atomic and xnpipe_bitmap has to be
> xnarch_atomic_t. But then find_first_zero_bit breaks. Is there some
> version for atomic arrays? I guess we have to open-code this, at least
> down to word-level...
>

You mean the op on the whole bitmap, right? Yes, we have a pb.

> Jan
> 


-- 
Philippe.

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